Life Sciences Commons^™

Unraveling Prevalence And Effects Of Deleterious Mutations In Maize Elite Lines Across Decades Of Modern Breeding, Shichao Sun, Baobao Wang, Changyu Li, Gen Xu, Jinliang Yang, Matthew B. Hufford, Jeffrey Ross-Ibarra, Haiyang Wang, Li Wang

Department of Agronomy and Horticulture: Faculty Publications

Future breeding is likely to involve the detection and removal of deleterious alleles, which are mutations that negatively affect crop fitness. However, little is known about the prevalence of such mutations and their effects on phenotypic traits in the context of modern crop breeding. To address this, we examined the number and frequency of deleterious mutations in 350 elite maize inbred lines developed over the past few decades in China and the United States. Our findings reveal an accumulation of weakly deleterious mutations and a decrease in strongly deleterious mutations, indicating the dominant effects of genetic drift and purifying selection …

Genomes To Fields 2022 Maize Genotype By Environment Prediction Competition, Dayane Cristina Lima, Jacob D. Washburn, José Ignacio Varela, Qiuyue Chen, Joseph L. Gage, Maria Cinta Romay, James Holland, David Ertl, Marco Lopez-Cruz, Fernando M. Aguate, Gustavo De Los Campos, Shawn Kaeppler, Timothy Beissinger, Martin Bohn, Edward Buckler, Jode Edwards, Sherry Flint-Garcia, Michael A. Gore, Candice N. Hirsch, Joseph E. Knoll, John Mckay, Richard Minyo, Seth C. Murray, Osler A. Ortez, James C. Schnable, Rajandeep S. Sekhon, Maninder P. Singh, Erin E. Sparks, Addie Thompson, Mitchell Tuinstra, Jason Wallace, Teclemariam Weldekidan, Wenwei Xu, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Objectives The Genomes to Fields (G2F) 2022 Maize Genotype by Environment (GxE) Prediction Competition aimed to develop models for predicting grain yield for the 2022 Maize GxE project field trials, leveraging the datasets previously generated by this project and other publicly available data.

Data description This resource used data from the Maize GxE project within the G2F Initiative [1]. The dataset included phenotypic and genotypic data of the hybrids evaluated in 45 locations from 2014 to 2022. Also, soil, weather, environmental covariates data and metadata information for all environments (combination of year and location). Competitors also had access to ReadMe …

Role Of Biotechnology In Creating Sustainable Agriculture, Saurav Das, Manjit Kumar Ray, Dinesh Panday, Piyush Kumar Mishra

Department of Agronomy and Horticulture: Faculty Publications

This narrative review paper discusses the role of biotechnology in the development of sustainable agriculture. The paper begins by defning sustanability and highlights the importance of biotechnology in establishing sustainable agriculture. Sustainable agriculture is an approach that prioritizes meeting current food and fiber production needs while conserving and enhancing natural resources for future generations. To achieve agricultural sustainability, it is necessary to strike a balance between economic viability, environmental stewardship, and social responsibility. This can be difficult, especially in the face of biotic and abiotic stresses such as pests, diseases, climate change, soil degradation, and water depletion. The prevalence of …

Classim: A Relational Database Driven Crop Model Interface, Dennis Timlin, David Fleisher, Maura Maura, Kirsten Paff, Wenguang Sun, Sahila Beegum, Sanai Li, Zhuangji Wang, Vangimalla Reddy

Department of Agronomy and Horticulture: Faculty Publications

Crop models are valuable tools for examining the interactions of cultivar characteristics, environment, and management practices, and how they affect crop growth and development. The difficulty in finding all the data needed to set up a simulation can often deter potential users from utilizing a crop model. Model interfaces are necessary to make these complex tools accessible to end-users who may lack the expertise needed to work with the models directly, but who would benefit from the information generated by the models. As crop models vary in terms of input and output structures, there is no one universally compatible interface, …

Tillage, Green Manuring And Crop Residue Management Impacts On Crop Productivity, Potassium Use Efficiency And Potassium Fractions Under Rice-Wheat System, Sandeep Sharma, Pritpal Singh, Hayssam M. Ali, Manzer Hussain Siddiqui, Javed Iqbal

Department of Agronomy and Horticulture: Faculty Publications

The conventional crop production practices including intensive tillage and open field crop residue burning in world’ largest rice-wheat system (RWS) are adversely affecting crop productivity besides deteriorating natural resources and ecosystems’ sustainability. In order to improve system productivity, potassium (K) use efficiency and apparent K balance, adoption of conservation tillage in a RWS with residue management is considered highly effective. We therefore, studied the effect of wheat straw retention and green manure (GM) in rice (main plot treatment), and tillage and rice residue management in subsequent wheat (sub-plot treatments) on crop productivity, K use efficiency and its transformation amongst different …

Conversion Of Native Grassland To Coniferous Forests Decreased Stocks Of Soil Organic Carbon And Microbial Biomass, Lidong Li, Elnaz Hosseiniaghdam, Rhae A. Drijber, Elizabeth Jeske, Tala Awada, J. Hiller, Michael Kaiser

Department of Agronomy and Horticulture: Faculty Publications

Aims Encroachment of woody species into grasslands is a global phenomenon that affects ecosystem services, including soil organic carbon (SOC) storage and microbial community structure. We determined stocks of SOC and soil microbial biomass as affected by conversion of grasslands to coniferous forests.

Methods We examined SOC and soil δ¹³C signatures under three vegetation covers: native grasslands, eastern redcedar (Juniperus virginiana), and ponderosa pine (Pinus ponderosa), at six soil depths (0 − 10, 10 − 30, 30 − 100, 100 − 170, 170 − 240, 240 − 300 cm). Fatty acid methyl esters (FAMEs) …

First Things First: Widespread Nutrient Deficiencies Limit Yields In Smallholder Oil Palm Fields, Hendra Sugianto, Juan Pablo Monzon, Iput Pradiko, Fatima A. Tenorio, Ya Li Lim, Christopher R. Donough, Sunawan, Suroso Rahutomo, Fahmuddin Agus, James Cock, Joni Amsar, Rana Farrasati, Ridho Iskandar, Juan I. Rattalino Edreira, Shofia Saleh, Heri Santoso, Antonius P. Tito, Nadib Ulfaria, Maja A. Slingerland, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Indonesia is the most important oil palm producing country. Nearly 40% of planted area is managed by smallholders, with yields well below the potential. Efforts to increase productivity have focused on the source of planting material, with little attention paid to plant nutrition.

OBJECTIVE: To assess the degree to which current productivity in smallholder oil palm fields is limited by nutrients in scenarios with distinct sources of planting material.

METHODS: We collected detailed data on leaf nutrient concentration from 30 fields to derive minimum sampling size needed to diagnose nutrient status. Subsequently, we collected data on …

Cover Crops And Soil Health In Rainfed And Irrigated Corn: What Did We Learn After 8 Years?, Humberto Blanco-Canqui, Sabrina J. Ruis, Katja Koehler-Cole, Roger Elmore, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Duration of cover crop (CC) management, CC biomass production, and other factors could impact how CC affects soil health. We studied the 8-year cumulative impacts of winter rye (Secale cereale L.) CC on soil physical, chemical, and biological properties in rainfed and irrigated no-till corn (Zea mays L.)-based systems in the western US Corn Belt. Average annual CC biomass production was 0.56 ± 0.51 Mg ha⁻¹ at the rainfed site and 0.98 ± 0.95 Mg ha⁻¹ at the irrigated site. After 8 years, CC improved particulate organic matter (POM) and mean weight diameter of waterstable aggregates …

Editorial: New Insights Into Mechanisms Of Epigenetic Modifiers In Plant Growth And Development, Volume Ii, Ming Luo, Tomasz Jacek Sarnowski, Marc Libault, Gabino Ríos, Jean-Benoit Charron, Nitin Mantri, Shoudong Zhang

Department of Agronomy and Horticulture: Faculty Publications

As we have learned, chromatin modifications, including histone modifications and DNA methylation, play a key role in plant development (Ng and Bird, 1999). However, accumulated evidence shows that, besides chromatin biochemical modifications, other epigenetic regulations such as chromatin architecture also function at a pivot point to regulate plant development (Zhang et al., 2021). In this Research Topic, five research papers describe multiple developmental facets mediated by different epigenetic mechanisms besides histone modifications. These manuscripts report experimental evidence or summarize recent advances in epigenetic regulations of some important developmental genes or development-related mechanisms. This Research Topic allows readers to learn of …

A Complete Telomere-To-Telomere Assembly Of The Maize Genome, Jian Chen, Zijian Wang, Kaiwen Tan, Wei Huang, Junpeng Shi, Tong Li, Jiang Hu, Kai Wang, Chao Wang, Beibei Xin, Haiming Zhao, Weibin Song, Matthew B. Hufford, James C. Schnable, Weiwei Jin, China Agricultural University, Hainan Yazhou Bay Seed Laboratory

Department of Agronomy and Horticulture: Faculty Publications

A complete telomere-to-telomere (T2T) finished genome has been the long pursuit of genomic research. Through generating deep coverage ultralong Oxford Nanopore Technology (ONT) and PacBio HiFi reads, we report here a complete genome assembly of maize with each chromosome entirely traversed in a single contig. The 2,178.6 Mb T2T Mo17 genome with a base accuracy of over 99.99% unveiled the structural features of all repetitive regions of the genome. There were several super-long simple-sequence-repeat arrays having consecutive thymine–adenine– guanine (TAG) tri-nucleotide repeats up to 235 kb. The assembly of the entire nucleolar organizer region of the 26.8 Mb array with …

Genome-Wide Association Analysis For Emergence Of Deeply Sown Rice (Oryza Sativa) Reveals Novel Aus-Specific Phytohormone Candidate Genes For Adaptation To Dry-Direct Seeding In The Field, Sandeep A. Sakhale, Shailesh Yadav, Lindsay V. Clark, Alexander E. Lipka, Arvind Kumar, Erik J. Sacks

Department of Agronomy and Horticulture: Faculty Publications

Dry direct-seeded rice (dry-DSR) is typically sown deeply to circumvent the need for irrigation, and thus seedling emergence is a crucial trait affecting plant stand and yield. To breed elite cultivars that use less water and are climate-resilient, an understanding of the genomic regions and underlying genes that confer emergence in deeply sown dry-DSR would be highly advantageous. A combined diversity panel of 470 rice accessions (RDP1 plus aus subset of 3K RGP) was evaluated with 2.9 million single nucleotide polymorphisms (SNPs) to identify associations with dry-DSR traits in the field and component traits in a controlled-environment experiment. Using genome-wide …

Do Cover Crop Mixtures Improve Soil Physical Health More Than Monocultures?, Humberto Blanco-Canqui

Department of Agronomy and Horticulture: Faculty Publications

Rationale and Purpose — Adding multispecies cover crop (CC) mixtures could diversify the current simplified crop rotations and enhance soil health more than monoculture CCs. Further, CC mixtures with diverse plant species could adapt better to changing climatic and environmental conditions than monoculture CCs. However, our current understanding of the soil benefits of CC mixtures is still limited. This review discussed whether CC mixtures are better than monoculture CCs to improve soil physical health.

Methods — All studies published up to May 25, 2023, comparing soil physical properties between CC mixtures and their constituents grown as monocultures were searched in …

Impact Of Nitrogen Availability On The Accumulation Of Vegetative Lipids In Sorghum, Leticia Felicio Pasqualino

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Sorghum (Sorghum bicolor (L.) Moench) is a versatile and prosperous feedstock crop for renewable energy production. With the increase in bioenergy demand, the production of higher oil content per biomass in a feedstock crop is a highly desirable trait for the biofuel conversion process yield. Especially if this outcome can be achieved using fewer inputs in the field, such as nitrogen. In microalgae species, nitrogen limitation has been associated with changes in the carbon storage metabolic pathway favoring triacylglycerol (TAG) accumulation. In this context, this study aimed to assess whether nitrogen starvation would result in a similar outcome in …

2018–2019 Field Seasons Of The Maize Genomes To Fields (G2f) G X E Project, Dayane Dayane Lima, Alejandro Castro Aviles, Ryan Timothy Alpers, Bridget A. Mcfarland, Shawn Kaeppler, David Ertl, Maria Cinta Romay, Joseph L. Gage, James Holland, Timothy Beissinger, Martin Bohn, Edward Buckler, Jode Edwards, Sherry Flint‑Garcia, Candice N. Hirsch, Elizabeth Hood, David C. Hooker, Joseph E. Knoll, Judith M. Kolkman, Sanzhen Liu, John Mckay, Richard Minyo, Danilo E. Moreta, Seth C. Murray, Rebecca Nelson, James C. Schnable, Rajandeep S. Sekhon, Maninder P. Singh, Peter Thomison, Addie Thompson, Mitchell Tuinstra, Jason Wallace, Jacob D. Washburn, Teclemariam Weldekidan, Randall J. Wisser, Wenwei Xu31, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Objectives This report provides information about the public release of the 2018–2019 Maize G X E project of the Genomes to Fields (G2F) Initiative datasets. G2F is an umbrella initiative that evaluates maize hybrids and inbred lines across multiple environments and makes available phenotypic, genotypic, environmental, and metadata information. The initiative understands the necessity to characterize and deploy public sources of genetic diversity to face the challenges for more sustainable agriculture in the context of variable environmental conditions.

Data description Datasets include phenotypic, climatic, and soil measurements, metadata information, and inbred genotypic information for each combination of location and year. …

Creeper Legume, In Conjunction With Biochar, Is A Potential Tool To Minimize Soil Erosion, Sujani De Silva, Priyantha Indralal Yapa, Kushani Mahatantila, Saurav Das, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Accelerated soil erosion and landslides are destructive consequences of road development and intensive agriculture in the central highlands of Sri Lanka. Properly designed vegetation covers can play a vital role in erosion control. Identifying a plant that can adapt to eroded land with a low-nutrient supply is critical for natural erosion management. A perennial creeper legume, Vigna marina, adaptable for marginal lands and used to control soil erosion in Australia, was introduced to Sri Lanka via the 2004 tsunami. The objective of this study was to assess V. marina under five different soil substrates, including a reference treatment (RT) …

Effectiveness Of Tadreb-B1 And 1-Feh W3 Kasp Markers In Spring And Winter Wheat Populations For Marker-Assisted Selection To Improve Drought Tolerance, Shamseldeen Eltaher, Mostafa Hashem, Asmaa A. M. Ahmed, P. Stephen Baenziger, Andreas Börner, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Due to the advances in DNA markers, kompetitive allele-specific PCR (KASP) markers could accelerate breeding programs and genetically improve drought tolerance. Two previously reported KASP markers, TaDreb-B1 and 1-FEH w3, were investigated in this study for the markerassisted selection (MAS) of drought tolerance. Two highly diverse spring and winter wheat populations were genotyped using these two KASP markers. The same populations were evaluated for drought tolerance at seedling (drought stress) and reproductive (normal and drought stress) growth stages. The single-marker analysis revealed a high significant association between the target allele of 1-FEH w3 and drought susceptibility in the spring …

Long-Term Conservation And Conventional Tillage Systems Impact Physical And Biochemical Soil Health Indicators In A Corn–Soybean Rotation, Anuoluwa O. Sangotayo, Jemila Chellappa, Udayakumar Sekaran, Sangeeta Bansal, Padma Angmo, Paul J. Jasa, Sandeep Kumar, Javed Iqbal

Department of Agronomy and Horticulture: Faculty Publications

Agricultural management practices tend to influence soil structure stabilization, mediating many physical, chemical, and biological processes in soils. Therefore, understanding the long-term effects of management practices on various soil health indicators is crucial to develop sustainable agricultural practices. This study aimed to assess the long-term conventional and conservation tillage effects on soil physical (aggregates) and biochemical (soil organic carbon [SOC], enzymes, and microbial biomass) parameters under a range of tillage practices in a corn–soybean rotation in Nebraska. The experiment was conducted at two locations as follows: (1) Concord site (36 years) with the three treatments: no-till (NT), disk, and moldboard …

Hybrid Allele‑Specific Chip‑Seq Analysis Identifies Variation In Brassinosteroid‑Responsive Transcription Factor Binding Linked To Traits In Maize, Thomas Hartwig, Michael Banf, Gisele Passaia Prietsch, Jia‑Ying Zhu, Isabel Mora‑Ramírez, Jos H. M. Schippers, Samantha J. Snodgrass, Arun S. Seetharam, Bruno Huettel, Judith M. Kolkman, Jiashi Yang, Julia Engelhorn, Zhi‑Yong Wang

Department of Agronomy and Horticulture: Faculty Publications

Background: Genetic variation in regulatory sequences that alter transcription factor (TF) binding is a major cause of phenotypic diversity. Brassinosteroid is a growth hormone that has major effects on plant phenotypes. Genetic variation in brassinosteroidresponsive cis-elements likely contributes to trait variation. Pinpointing such regulatory variations and quantitative genomic analysis of the variation in TF-target binding, however, remains challenging. How variation in transcriptional targets of signaling pathways such as the brassinosteroid pathway contributes to phenotypic variation is an important question to be investigated with innovative approaches.

Results: Here, we use a hybrid allele-specific chromatin binding sequencing (HASChseq) approach and …

Evaluating Planting Green And Herbicides For Integrated Weed Management And Their Effect On Soil Properties In Corn And Soybean In Nebraska, Trey Stephens

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Producers across the Midwest are finding new ways to implement cover crops into cropping systems and the practice of “Planting Green” is one of the newest uses of cover crops. When planting green, producers plant their row crops into actively growing cover crops and terminate the cover crop at time of planting or shortly after planting. This practice would allow for higher biomass accumulation of the cover crop and could aid in weed management of herbicide-resistant weeds. The objective of the first two studies was to evaluate planting green and its effect on soil-applied residual herbicides, weed management, dicamba/glyphosate-resistant soybean …

Genomic Selection For Yield And Seed Composition Stability In An Applied Soybean Breeding Program, Benjamin Harms

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Stability traits are of primary importance in plant breeding to ensure consistency in phenotype across a range of environments. However, selection efficiency and accuracy for stability traits can be hindered due to the requirement of obtaining phenotype data across multiple years and environments for proper stability analysis. Genomic selection is a method that allows prediction of a phenotype prior to observation in the field using genome-wide marker data and phenotype data from a training population. To assess prediction of stability traits, two elite-yielding soybean populations developed three years apart in the same breeding program were used. The individuals in each …

Plasticity Of Sorghum Biomass And Inflorescence Traits In Response To Nitrogen Application, Kyle M. Linders

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen is an essential nutrient required for growth and development in plants. Insufficient nitrogen availability can reduce vegetative growth and grain yield. However, nitrogen is a costly input for farmers, is energy intensive to manufacture, and runoff of excess nitrogen fertilizer impacts water quality. Compared to its close relative, maize, sorghum has much greater resilience to nitrogen and water deficit, and heat stress, allowing sorghum to be grown with fewer inputs and on marginal land. Variation in total biomass accumulation and grain yield between sorghum accessions, as well as between nitrogen conditions, can be largely explained by differences in vegetative …

Irrigation-As-A-Service For Smallholder Farmers, Ishani Lal

Department of Agricultural Economics: Dissertations, Theses, and Student Research

Irrigation is a crucial management practice that can help increase food security among smallholders globally while mitigating climate change impacts. High-efficiency irrigation technologies such as drip kits and sprinkler systems are relatively expensive and smallholder farmers cannot afford them to buffer crop yields against low precipitation. In many developing countries, farmers participate in robust informal markets for renting and sharing of irrigation equipment. Such services may be operated by farmers or via a third party such as irrigation start-ups, water user associations, non-governmental organizations, or even government agencies. These services are referred to collectively as Irrigation-as-a-Service (IaaS).

The objective of …

A Deep Learning Framework For Processing And Classification Of Hyperspectral Rice Seed Images Grown Under High Day And Night Temperatures, Víctor Díaz-Martínez, Jairo Orozco-Sandoval, Vidya Manian, Balpreet K. Dhatt, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

A framework combining two powerful tools of hyperspectral imaging and deep learning for the processing and classification of hyperspectral images (HSI) of rice seeds is presented. A seed-based approach that trains a three-dimensional convolutional neural network (3D-CNN) using the full seed spectral hypercube for classifying the seed images from high day and high night temperatures, both including a control group, is developed. A pixel-based seed classification approach is implemented using a deep neural network (DNN). The seed and pixel-based deep learning architectures are validated and tested using hyperspectral images from five different rice seed treatments with six different high temperature …

Entropy And Energy Profiles Of Chemical Reactions, Johannes C. B. Dietschreit, Dennis J. Diestler, Rafael Gómez-Bombarelli

Department of Agronomy and Horticulture: Faculty Publications

The description of chemical processes at the molecular level is often facilitated by use of reaction coordinates, or collective variables (CVs). The CV measures the progress of the reaction and allows the construction of profiles that track the evolution of a specific property as the reaction progresses. Whereas CVs are routinely used, especially alongside enhanced sampling techniques, links between profiles and thermodynamic state functions and reaction rate constants are not rigorously exploited. Here, we report a unified treatment of such reaction profiles. Tractable expressions are derived for the free-energy, internal-energy, and entropy profiles as functions of only the CV. We …

Divergent Metabolic Changes In Rhizomes Of Lowland And Upland Switchgrass (Panicum Virgatum) From Early Season Through Dormancy Onset, Nathan A. Palmer, Gautam Sarath, Michael J. Bowman, Aaron J. Saathoff, Serge J. Edmé, Robert B. Mitchell, Christian M. Tobias, Soundararajan Madhavan, Erin D. Scully, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

High-biomass-yielding southerly adapted switchgrasses (Panicum virgatum L.) frequently suffer from unpredictable winter hardiness at more northerly sites arising from damage to rhizomes that prevent effective spring regrowth. Previously, changes occurring over the growing season in rhizomes sampled from a cold-adapted tetraploid upland cultivar, Summer, demonstrated a role for abscisic acid (ABA), starch accumulation, and transcriptional reprogramming as drivers of dormancy onset and potential keys to rhizome health during winter dormancy. Here, rhizome metabolism of a high-yielding southerly adapted tetraploid switchgrass cultivar, Kanlow—which is a significant source of genetics for yield improvement—was studied over a growing season at a northern …

Herbicide Drift Vs. Crop Resilience – The Influence Of Micro-Rates, Milan Brankov, Bruno Canella Vieira, Miloš Rajković, Milena Simić, Vukadinović Jelena, Violeta Mandić, Vesna Dragičević

Department of Agronomy and Horticulture: Faculty Publications

A greenhouse study was conducted to test the effects of low herbicide dose exposure on different crops measuring visible damages, plant height, leaf area, and dry matter. Seven crops were tested: lettuce (Lactuca sativa L.) cv. Novosadska majska maslena, oil pumpkin (Cucurbita maxima Duch) cv. Olivija, oilseed rape (Brassica napus L.) cv. NS Ras, pepper (Capsicum annuum L.) cv. Kurtovska kapija, soybean (Glycine max (L.) Merr) cv. ZP Laura, sunflower (Helianthus annuus L.) cv. NS Kruna, and tomato (Solanum lycopersicum L.) cv. Dunavski Rubin. Herbicide dicamba in the range of 0.14 to 1 …

Late Postemergence Glufosinate-Based Programs For Glyphosate-Resistant Palmer Amaranth Control In Dicamba/Glufosinate/Glyphosate-Resistant Soybean, Vipan Kumar, Jatinder S. Aulakh, Rui Liu, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Watson) is widespread in the Central Great Plains. Introduction of newly developed dicamba/glufosinate/glyphosate (DGG)-resistant soybean varieties allows postemergence (POST) applications of dicamba and glufosinate for in-season control of GR Palmer amaranth. Limited information exists on the effectiveness of glufosinate applied late-POST for tall (70–90 cm) GR Palmer amaranth control in DGG-resistant soybean. The objectives of this study were to (1) determine the effectiveness of late-POST glufosinate-based programs for GR Palmer amaranth control, and (2) determine the impact of those programs on soybeans grain yields. Ten glufosinatebased programs were tested in a field …

A Leaf-Level Spectral Library To Support High-Throughput Plant Phenotyping: Predictive Accuracy And Model Transfer, Nuwan K. Wijewardane, Huichun Zhang, Jinliang Yang, James C. Schnable, Daniel P. Schachtman, Yufeng Ge

Department of Agronomy and Horticulture: Faculty Publications

Leaf-level hyperspectral reflectance has become an effective tool for high-throughput phenotyping of plant leaf traits due to its rapid, low-cost, multi-sensing, and non-destructive nature. However, collecting samples for model calibration can still be expensive, and models show poor transferability among different datasets. This study had three specific objectives: first, to assemble a large library of leaf hyperspectral data (n=2460) from maize and sorghum; second, to evaluate two machine-learning approaches to estimate nine leaf properties (chlorophyll, thickness, water content, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur); and third, to investigate the usefulness of this spectral library for predicting external datasets …

Characterization Of Physical And Biochemical Traits In Wheat And Corn Plants Using High Throughput Image Analysis, Kantilata Thapa

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Plant phenotyping has been recognized as a rapidly growing field of research due to the labor-intensive, destructive, and time-consuming nature of traditional phenotyping methods. These phenotyping bottlenecks can be addressed by advancements in image-based phenotyping like RGB and hyperspectral imaging for the assessment of plant traits important for breeding purposes. This study aims (1) to characterize the physical and biochemical traits of wheat and corn plants using RGB and hyperspectral imaging in the greenhouse, and (2) to estimate leaf nitrogen (N), phosphorus (P), and potassium (K) content using hyperspectral imaging and an analytical spectral device (ASD spectrometer) and compare the …

Experimentation On Nebraska Farms For Sustaining Soil Health Management, Fernanda Souza Krupek

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Soil health management practices have increasingly been promoted across US agroecosystems to address many interrelated environmental and economic food system challenges. Sustaining conservation behavior – through farmer’s adoption and continued use of practices – is key for achieving many soil health-related intended social-ecological benefits. Using a range of scientific methods, from lab-based experiments to on-farm research to farmer interviews, the overall objective of this dissertation research was to explore soil and human dimension considerations to design farming and knowledge transfer systems for sustaining soil health management in the US Midwest. In a multivariate analysis of ten on-farm research sites, we …